#include<stdio.h>
main()
{int iNum;
int i1,i2,i3,iSum;
printf("please input a integer(100-999):");
scanf("%d",&iNum);
i1=iNum%10;
i2=iNum%10%10;
i3=iNum%100;
iSum=i1+i2+i3;
printf("the Sum is: %d",iSum); 
}
